Gem tach magnet

How many poles on a standard Gem tach magnet?

All the same?

Mine is a 2000 with 3.5hp ge motor.

Designing a project and to lazy to take anything apart.

Is this correct?
From another post by OH.


You buy a 2 pole magnet. (original is 4) about 50 bucks."

Standard equipment magnet is 4 pole

Put a counter on the tach signal and counted pulses for one full wheel revolution.

Marked a tire and rolled it in the shop.

35 pulses divided by 4 is 8.75.

I’m very surprised. Car has loads of torque. Except for towing why lower ratios?

Almost forgot.
Do all models use the same plug?

GEM went thru various ratios, 8.9 with 3,5hp 10.5 with 5hp 12,44 and back to 10.5

8.5 is great for flat land. 10.5 is a good all purpose unit suitable for general all around use in any terrain. 12.44 is good for heavy loads and hills. The trouble with the 12.44 is that when violators (certainly none of our members) modified the carts to go beyond legal restraints the motors would not tolerate the over revving. This is one of the big reasons Polaris returned tothe 10.35 ratio in recent years cart.

Outside our forum, outlaw types favor the 8.9 gearbox with Marlon’s or R4F 7.5HP motors These “Hot Rods” can exceed 40 MPH. Naturally our members, being conservative Republicans, would never consider shattering rules of this ilk.:smiley:

What say you

8.9 is fine for me. I only counted two tire turns. 8.9 would be about 71 pulses, which I rounded off to 35 per rotation.

Reason I asked about the plug. I might make up a counter/tach that plugs in, if it was useful on other models.

The plug is generic to all models.

No need to. Can be calculated from MPH. Pm me and I will copy you on my spread sheet Basic purpose of the spread sheet is to determine RPM with a given tire size and gear ratio.

Now you tell me! :smiley:

I’ve got it now in any case.